Archival encounter: Monotremes from past to present

This is Shaw's first description of the platypus.

It's actually not that bad, right?

No, there's little that's wrong with it. It has a forked tail, which the animal doesn't. Yeah.

But otherwise the portrayal is really very good.

And this is some of the description because it's just great. Of all the mammalia yet known, it seems the most extraordinary in its confirmation, exhibiting the perfect resemblances of the beak of a duck engrafted on the head of a quadruped. It naturally excites the idea of some deceptive preparation by artificial means.

That's right.

I remember the stories of them poking and prodding at the beak to see where the stitching might be. So, yes, you know, to see where the beak had been stitched on to the body. Exactly, to see if this was some kind of ruse. Yeah. But no, the image is great.

And there's another. Oh, some of the anatomy here.

Yeah, absolutely.

So we see the forefoot with its, you know, its great webbing, and we have the duckbill. That's the underside of the bill where you can see the lower lip and these sort of serrated portions of the side of the lip that it grinds things up with mouth open.

So this is the first, the original description, really.

Yeah.

And you know, today we think of one of the most remarkable aspects of these animals as being the fact that they're egg-layers.

And it wasn't known for another 50 years either. Yeah.

It was quite some time. In fact, longer than that. It was about 100 years officially. Although along the way, many made observations that suggested that these did lay eggs.

And of course, if anyone had asked the First Nations people who knew these animals best, they would have instantly explained to them exactly how they reproduce.

And that did happen.

Yeah, but it was only until about 100 years later that a monograph was published where a student came from Cambridge and did a study out in the bush, found that they were laying eggs and was able to get those eggs and document their anatomy in fine detail.

These are some early illustrations of platypuses. So before this work on reproduction had been done.

Well, what do you think?

I do like it. I like it. That's a well-fed platypus.

I like all these early ones. Exactly. I've no doubt it's based on an overstuffed specimen, you know, a skin that's been absolutely massively packed full of straw or paper or something. But it also looks like it's bellowing or doing some sort of thing like that. But no doubt, again, the way that it had been stuffed and prepared. But again, most of the fundamental anatomy is there. The beak and the small eye, the little ear slit, the way that the forelimb and the hind limb look and the tail, it's all there.

And actually, there's another Australian Museum connection to the platypus too, because correct me if I'm wrong, but it was in the 1820s that they started to realise that platypuses were mammals.

During the mid-1820s, there was a real desire for specimens so that they could, you know, do more of this discovery back in England. And the naturalists and the scientists in England started complaining that specimen supply wasn't reliable enough and that they needed a museum in Sydney in order to facilitate this sort of trade. Part of the origin story of this place. Absolutely.

There's a really, really nice thread. This one that's, this is interesting too, showing the inside of the mouth and again, the shape's somewhat strange.

This is a really nice story too about scientific authority and who gets to describe these animals and what's the status of field observations both of, of course, of Aboriginal people who would have known all of this straight up, but also of settler naturalists who probably also had this information but needed to get a stamp.

Absolutely, right. From a British authority before they were taken seriously, which is maybe one of the reasons why these sorts of discoveries took so long.

Yes, all along, from the earliest days of settlement, you know, both accounts from First Nations people, Aboriginal people of here in the area of Sydney and all of the up and down the East Coast and yes, of other settler naturalists talking about finding eggs, talking about capturing animals, seeing them lay eggs overnight. And even then it just wasn't quite good enough. The authority wasn't established there. There wasn't someone with the right sort of credentials.

And it's an interesting story about the Australian Museum in that case too, like how the museum built its authority through that, you know, the slow work of field observation and of making field observations have the sort of status that a dissection might have back in a lab in England. But you can have that. But unless you have us, you don't have the full story.

So that's, you know, be nice because, you need us.

Yeah.

You have access to the real information, you know, I think that's right. As a scientist that works a lot on specimens, I always find that animals we don't know very much about, you know, through a dissection or through an examination of anatomy. It's really illuminating. Like it gives you a lot of clues about what this animal's life must be like, you know, what its senses are like, what it eats, where you know, how it interacts with its environment. Just basically, you know, what it does for a living.

But you don't actually know any detail beyond the basics until you are able to go and study these animals in the field.

I think we've got an echidna in here, too.

Oh, yeah.

Have a look and see what that one's like.

Yeah.

Yeah, I just, you know, hold my breath when I see that, amazing.

Something that's rarely seen is the differential tale of the echidna at the back.

But there we see Gould has portrayed that as a separate part of the body a little bit.

The huge claws that speak to the fact that this is the great digging mammal of Australia.

And that long tongue that protrudes out of that toothless kind of tube of a mouth to capture social insects.

Things like ants and termites.

Yeah. And surprisingly lively.

If made from specimens.

Yeah.

Although he had, of course, been here and probably seen them.

He would have seen them by then and

Absolutely you know, in probably in many parts of Australia.

Now, one thing I often think about because I work a lot in New Guinea.

Is that, you know, we see Shaw around 1800, you know, describing the echidna the first time that Western science comes to know this animal. We see a hundred years later, essentially, Caldwell proving essentially that these things lay eggs.

My favourite mammal of all is this Long-beaked Echidna, which is the world's largest egg-laying mammal. But even the idea that it's an egg-laying mammal remains a little bit the realm of supposition. The reason being is that no Western scientist has ever been able to document a nest, or an egg of this animal to this day.

-Wow.

So no one has seen the way that this animal reproduces which is an extraordinary thing.

Well, no Western scientists have seen it.

That's what I mean. Exactly.

Someone has seen it. Of course.

That said, it's either a great mystery or a really tightly held secret because it's so little known.

Whenever I have worked in New Guinea and I've worked with dozens and dozens and dozens of very senior men to try to learn as much as we can about mammals, including this very special mammal.

No one has ever been able to tell me definitively like they'll tell you about so many types of other aspects of biology, exactly how this animal reproduces, which is extraordinary.

So it remains somewhat unknown.

The only way that we know.

We know it's an egg-layer because it's so closely related to these other species.

And there is one museum specimen that was prepared as a fluid in alcohol, that has an egg inside the body, inside what we call the oviduct before it's been birthed.

But I think it's an amazing thing that even, you know now well into the 21st century, some of these monotreme mysteries still persist.

Well, and also that we still maybe don't know how to ask the right questions, or that there's some things that people who know these things, don't want us to know.

That might be exactly what the case is.

These things might and perhaps must be absolutely specially guarded pieces of information.

So this is one of my favourite illustrations that Peter has ever done, and we commissioned this. This is the oldest monotreme known in the fossil record and the smallest monotreme ever known by a really good margin. So this animal would have weighed about 40 grams. So the size of something like a rodent in modern times. It was a very toothy animal. And we have the teeth of the animal. That's what we know it best from. And so Peter's done a great job of illustrating the many different teeth. That's a little bit unexpected because by the time we get to modern monotremes, the living echidnas and platypuses are all toothless animals. And what we can see in the fossil record of monotremes is that over time, steadily, from the time of the dinosaurs through to today, they lose those teeth over time.

So does that mean that this is eating a different diet? Perhaps, so we know from what it's eating. It's clearly eating insects, probably looking for it in the leaf litter and under the moss. Peter's illustrated this with an image of Cretaceous vegetation. Exactly. So he's captured this environment, you know, maybe living, maybe if it's a waterside animal capturing vegetation from the time. But already there is an indication from the way the nerves connected into the front of the face of this animal that it is probably on its way to developing the sixth sense of monotremes, which is the electro-sensory organ that they have in their face, the duckbill of the platypus.

Because another thing I notice about this is how much bigger the eye is. Yeah, that's true. Exactly. So the eye is already a little bit bigger. It's already getting small. We already don't see any external ear. We're implying about some of the features based on what we know of other monotremes. But this is a really good illustration, I think, of the earliest monotremes. It's just beautiful. 'Teinolophos' is the name of this animal. 'Teinolophos trusleri.' It's an animal we've known existed from science that was done in the late 1990s. What we did in this paper is we took a closer look at this first of the monotremes and realised it's so different than everything that comes after that it deserves its recognition as its own taxonomic family. Right. You know, the echidnas are their own family, the platypuses are their own family. This was an early family unto itself. And it's not very often that we as zoologists get to name something a category as high as a family. So that was very, very exciting.

How did you choose a name for that? Well, that's easy because we can choose to name species whatever we like and genera, but by the time you choose a family, it's based on the name of a genus. So for 'Teinolophos,' its family name has to be 'Teinolophidae.' This is 125 million years old. This is when that animal was alive, again the time of the dinosaurs, and the Cretaceous.

These are beautiful, Kris. Aren't they. So those are, Peter Schouten, illustrated these for a paper that we published earlier this year on the origins and the whole evolutionary history of monotremes. They're lifesize. Oh, is that lifesize? Wow. It's lifesize. So this was the largest monotreme that ever has been discovered so far. Like, wow. That would be a thing to encounter. It really would, really would. And it seems to have, based on its age, overlapped with people in Australia. So you know, it's extinct now for a long time. But to be fair, the entire external anatomy of the animal is envisioned and dreamed up because we only have its skeleton, but we have much of its skeleton which is great. And the skeleton shows that it's larger than these living long-beaked echidnas by a remarkable measure. So it's quite a bit bigger than any living echidna. And there's also some aspects of the hind limbs that show that it was probably pretty good at standing upright, perhaps even climbing. And so we chose to illustrate this as, this animal is only known from the southwest of Western Australia. And in these forests that are there today, there are kinds of termites that live only up in the trees. And you can imagine these animals. This actually lived alongside three other different kinds of echidnas at the time: short-beaks, long-beaks and another big echidna from the ice ages of Australia. So we would've had four echidnas, all trying to make a living in the same sort of environment, and of course that means they all had to do something slightly differently. And this being so big and upright and perhaps climbing, we thought this is most likely to take advantage of the huge number of social insects that can live up, up in trees. Hence the way we've illustrated this.

This is great, as a scientific illustration too. Like it's got so much information in it. I mean, we know what it eats. Where the environment is. We've got some scale with this little bird. Exactly. And that's a willie wagtail, which is ubiquitous across most of Australia, including in the southwest. So it means that when people encounter the painting, they can take a bird from their own backyard and instantly know, Ok, this is the size we're looking at. Yeah. I really like that. The animal itself, it's a genus that we named as new to science based on a skeleton that had already been known for quite some time in the museum in Western Australia. So the name of this animal is 'Murrayglossus', we named it after echidna biologist named Peter Murray, who's spent much of his career looking at fossil monotremes. And so it was an easy decision to choose to name a fossil echidna after someone who'd spent so much time on this sort of work. But it's a Pleistocene animal. We don't know too much about it because we only have bones from a single cave in Western Australia, a mammoth cave, which is an important fossil site for Pleistocene animals in Australia. But it lived alongside animals like in Western Australia, like thylacines, like marsupial lions, thylacoleo, alongside many larger kangaroos that are now extinct and other megafauna. So this is as big as monotremes have known to have ever gotten. It's not exactly megafaunal compared to a rhino-sized diprotodontid. But as far as monotremes go, it's a megafaunal monotreme. Significantly bigger than what we have now.

Now we'll look at some of the fossils here we've brought up from the paleontology collection. This is a monotreme that's been named 'Steropodon' and this is the first monotreme. It's in its own family like Teinolophos - Steropodontodae. But it's the first monotreme in the fossil record, about 100 million years old that starts to look very much like a platypus. So this is on the trail to the modern monotremes. Looking like a platypus. And if we lift this up, one of the things that's so astonishing about this is that it's an opalised fossil. So this is a fossil that's made of opal. This is extraordinary. This is from the Lightning Ridge site of New South Wales where opals are mined. So was this a serendipitous find? Was somebody looking for it? Well, it was serendipitous, but people were on the lookout. This was sent to Mike Archer and Tim Flannery back in the 1980s. It's beautiful. It is beautiful. It's one of only a handful of monotreme fossils we have from the entire Australian record. You can also see at this point, platypus-like monotremes remained pretty toothy. We see some premolars and molars here and over time, over the next 100 million years, steadily the platypus-like lineage of monotremes steadily loses those teeth.

So why do we have those gaps then like why are they not more of these? It's because it's really hard to find fossils of the right age in Australia. They're pretty delicate and they're really rare. And so things like bigger animals like turtles or even dinosaurs are coming out of some of these Cretaceous deposits in much bigger numbers than these tiny toothy mammals. Yeah, I can imagine that. And then this one is a more recent fossil. This is a fossil of an echidna. So here we see it's, this is the brain, these are the eyes. And this is the snout, the rostrum, the long beak moving forward. It's broken off at the halfway point of the beak and it's broken at the back of the brain. But there's enough here to realise that this is an...

Here we have some taxidermied specimens of platypus. This is a lovely one. This is something that was at one point on display, so it's posed in quite a lifelike frame of reference. It's as if it's crawling along the ground, and looking at it, you can see some of the important features of the animal. You can see this incredible, leathery duck-like beak that has so captured the imagination of people, unusual amongst mammals. And this is the seat of the electro-sensory organ, the sort of sixth sense of monotremes. It sits in the front of this beak. Tiny eye, very small opening for the external ear.

Big paddling front feet with long claws, good at digging, and a lot of webbing in the feet. Good at paddling. Tucked up underneath, when the animal's walking around, we can see the back feet as well. Five long, kind of sickle-shaped claws, again very good for digging. Also good for stabilising the animal as it's swimming. You can see this one is a female. It's lacking what we'll show in another skin, the spur, the hind foot spur, which is the venomous spur of the male platypus. And we have kind of a thick, powerful, muscular tail that allows for propulsion through the water. The fur, if you were to touch it and feel it, feels sort of oily and waterproof to the touch, it glistens a little bit because it has this lustrous waterproof aspect to it.

Back in this area, we have the part of the body called the cloaca. This is one hole for where monotremes do everything. They urinate, they defecate, and they reproduce. And the fact that it's one hole, unusual among all the other mammals, which have more complicated reproductive anatomy, that's where the name monotreme comes from. "One hole."

This is one that's stuffed in a less lifelike pose as what we call a study skin. It's just flat and straight, and it's meant to live not on display, but in a drawer. And this is one of our study specimens then that's largely used by visiting scientists and internal scientists here at the museum to help understand the biology of the platypus. Again, it's prepared in such a way that all the principal features are really easily seen and understood. Here we see on the male this quite large hind foot spur, which connects to a duct that goes up sort of just below the knee of this animal, a big gland called the crural gland, which produces venom. This is the only mammal that produces venom out of the hind foot of its body, a very strange sort of anatomy, an indication that platypuses are so different from other mammals that, along with the echidnas, they've been on their own branch of the family tree for a very, very, very long time.

So, Vanessa, I'll show you the two main varieties of echidna. Here we have the smaller one, the short-beaked echidna, which has this straight and short beak, and then the larger kind, which is called the long-beaked echidna. It has a down-curved long rostrum. So those are the principal differences between these two. The short-beaked animal lives throughout the continent of Australia and also through much of New Guinea. And today, the long-beaked echidna is found only generally in quite remote rainforested areas of New Guinea.

Yeah, both have their principal defence being spines across the body. Like platypuses, echidnas have no teeth, so they have a completely toothless mouth. The beak is a long, bony tube. It has a tongue that can shoot out quite some length to gather up insects or other invertebrates. A little bigger eye than the platypus, this is an animal that's moving around sometimes during the day and needs to see above water. You can see the external ear kind of situated a little bit back here behind the eye. We can see really powerful digging claws on these animals.

-Have you ever come across them in the wild?

-Absolutely, yes. The first thing they try to do is dig straight down into the earth and start to disappear right in front of your eye. You can touch them if you like. Just be careful because they're so prickly, and you can get a feel for what it would be like to encounter one.

Yeah, wow. The spines are all attached to an amazing kind of system of muscle along the back, and so it can move them in all various directions. And it's really quite powerful. The entire animal, in fact, is sort of made of muscle, with its powerful digging arms and legs.

You can see in the back we've got this long claw here. This is especially good at grooming. An animal like this has to be able to get under these spines and clean out things like ticks and fleas and give itself a good scratch. So that's part of having these really long back claws. This is my favourite mammal of all. I'm a mammalogist.

Big call, big call.

It is a big call.

It used to be that people would ask me, I've named and described many species of mammals, "What's your favourite mammal?" And I say, "I can never say." Isn't that like having a favourite child? It's a bit like that, maybe, but I just readily now admit that it's this animal. Why? Because it's the largest egg-laying mammal and it's one of the strangest animals on the planet. There's still so little that we know about it.

And its New Guinea home.

Yeah. And so this is an animal that lives in fairly cold climates in the upper mountain rainforests and sub-alpine fields of New Guinea today. With this long beak, it eats quite different things than the short-beaked. The short-beaked echidna eats social insects, so it eats termites and ants. This eats animals that can be found kind of deep in the soil, underneath the leaf litter of rainforests. So especially things like earthworms and really big pupae, things like beetles.

So that echidna specimen there, is that from a cold place because it's furrier, as well? It is. The species itself comes from a fairly cold place. And this is an absolutely beautiful preparation of this animal. The individual animal was an animal that lived for a long time, many years, maybe even decades at the Taronga Zoo.

Oh, Ok. Yeah.

Well looked after then.

Well looked after.

And, you know, a famous animal in its own right. There is only one left at the zoo. And I think it's the only long-beaked echidna in captivity on display anywhere in the whole world. So this is a very rare animal, even in New Guinea. And this animal was a crowd pleaser and a special animal, kind of a celebrity creature, that ended up, after its life, taking on a new life here at the museum. And her name, in fact, is Sheila. So, if any zoo employees come here, they would come here and look at Sheila with great reverence, an animal they remember and love. Yeah. But also a part of a long tradition of us receiving animals from the zoo. Exactly right, exactly right. And it's often really useful to have animals where their biology was well known for their lives, that they lived at the zoo, and then we have their bodies, their remains afterwards for people to come and study their afterlives as well. So it's quite useful to connect the two.